Halloween Preview... Witches, Ghosts, and Carl Sagan?

Jim Parsons’s Sheldon dressed as the Doppler Effect in The Big Bang Theory’s first season, but the character’s geek-out costumes didn’t begin there. “We were looking for something science-based, so why not Carl Sagan?” says exec producer Steven Molaro of the genius’s getup at age 10. For Sheldon (Iain Armitage, above left, with Wyatt McClure, Raegan Revord and Ryan Phuong), the candy haul is less of a concern than folks’ ignorance of the famed astrophysicist. Plus, Sheldon’s mom, Mary (Zoe Perry), asks drama teacher Mr. Lundy (Jason Alexander) to help with the church’s Hell House, which, Molaro notes, “depicts scenes of sin in an effort to lead people to God.” Holy sloth! —Jim Halterman

Ron Tom/ABC

Single Parents

Wednesday, Oct. 24, 9:30/8:30c, ABC

It’s the freshman sitcom’s first Halloween and, not surprisingly, Will (Taran Killam, left, as Ben Franklin) is superexcited. The others in his circle of moms and dads, not so much. But when his daughter, Sophie (Marlow Barkley), announces she’s outgrown trick-or-treating, the gang rallies to cheer him up. In other holiday headlines: Poppy (Kimrie Lewis) convinces Douglas (Brad Garrett) to wear a costume, and the results are humiliating. “He meets the woman of his dreams,” says executive producer JJ Philbin, “while dressed as a chipmunk.” —JR

FOX

The Simpsons

Sunday, Oct. 21, 8/7c, Fox

For each year’s Halloween-themed “Treehouse of Horror” anthology, “we go through dozens of ideas before settling on the three and a half that are the best,” says exec producer Al Jean. So after 28 of the fan-favorite episodes (98 ideas!), what made the cut for 2018? A take on Jurassic Park in which Mr. Burns opens a retirement home, plantlike body snatchers running amok in Springfield and an epic oyster-eating contest that lands Homer in the tentacles of the mythical Cthulhu (left). “We did The Shining 14 years after its release,” Jean says of the evergreen spoofs. “There’s no expiration date. Why not Cthulhu?” —John Russell

Tony Rivetti/ABC

Modern Family

Wednesday, Oct. 24, 9/8c, ABC

In the costume department, smarty-pants Alex (Ariel Winter) as Supreme Court Justice Ruth Bader Ginsburg is good—but over-the-top Cam (Eric Stonestreet, above right, with a buggy Ty Burrell) as Duchess Meghan Markle is inspired! Writers chose the look “because it makes no sense at all,” says executive producer Steven Levitan with a laugh. Don’t expect the sitcom to overflow with Halloween fun, though. “The family gets hit with very unexpected news,” Levitan reveals. “It affects them all and will for a while.” Good grief (which also happens to be the title of this game-changing episode). —Jim Halterman

Scott Everett White/The CW

Crazy Ex-Girlfriend

Friday, Oct. 19, 9/8c, The CW

The Twist. The Pony. The Cringe? The musical dramedy’s latest dance demonstrates “the embarrassed cringe we all feel when confronted with uncomfortable memories,” says exec producer Aline Brosh McKenna, and springs from Rebecca’s (Rachel Bloom) shame over her dark past. Too stricken to leave her house, “she decides it’s haunted by a ghost who needs her help to be liberated,” McKenna adds. Which all somehow brings about the Cringe number. Creepy security guard Castleman (Patton Oswalt, above, with Gabrielle Ruiz, Bloom, Vella Lovell and Donna Lynne Champlin), now on cemetery duty, even returns to join in! —JH

Tony Rivetti/ABC

Black-ish

Tuesday, Oct. 30, 9/8c, ABC

The comedy’s Halloween episode will send a shiver down your spine, but not for reasons you’d expect. Dre and Bow (Anthony Anderson and Tracee Ellis Ross, below), anxious over how twins Jack (Miles Brown) and Diane (Marsai Martin) are faring on the seventh-grade social circuit, take action. “They try to impress Jack and Diane’s classmates by hosting a haunted house,” says executive producer Jonathan Groff, and end up way overshooting the mark. Warns exec producer Kenny Smith, “Dre and Bow aren’t the type to not give 100 percent.” Bonus: Black Panther costumes! —Ingela Ratledge

A 10-year-old in an astrophysicist costume is just one of the many TV treats awaiting you this season. Boo!